This invention relates to a semiconductor device.
A power supply circuit such as a DC-DC converter comprises a high-side switching element connected between an input terminal and an inductor and a low-side switching element connected between the inductor and a ground. The high-side switching element and the low-side switching element are alternately switched ON/OFF. The DC-DC converter outputs an output voltage lower than an input voltage at a latter stage of an LC filter (for example, JP-A 2002-281744 (Kokai)).
The inductor is generally used to be an external add-on component with respect to a power IC in which switching elements and drivers and so forth are formed as integrated circuits. And in this case, a drain terminal of the low-side switching element is an external terminal of the power IC and can be exposed to ESD (Electro Static Discharge). The power IC is required not to be broken, even if the ESD surge applies into the external terminal.